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From:   Peter Chen <peter.chen@nxp.com>
To:     Tang Bin <tangbin@cmss.chinamobile.com>
CC:     "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Subject: Re: [PATCH] usb: hcd: fix the error check
Thread-Topic: [PATCH] usb: hcd: fix the error check
Thread-Index: AQHWdu2wIt6TNfBTb0KQoyimK4tKialGkX2A
Date:   Mon, 24 Aug 2020 02:39:50 +0000
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On 20-08-20 20:20:38, Tang Bin wrote:
> In the function usb_add_hcd(), usb_phy_roothub_alloc()
> can return NULL in some cases, so IS_ERR() doesn't meet
> the requirements. Thus fix it.
> Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
> ---
>  drivers/usb/core/hcd.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>=20
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index aa45840d8..b73a92ee1 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2633,8 +2633,9 @@ int usb_add_hcd(struct usb_hcd *hcd,
> =20
>  	if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
>  		hcd->phy_roothub =3D usb_phy_roothub_alloc(hcd->self.sysdev);
> -		if (IS_ERR(hcd->phy_roothub))
> -			return PTR_ERR(hcd->phy_roothub);
> +		if (IS_ERR_OR_NULL(hcd->phy_roothub))
> +			return hcd->phy_roothub ?
> +					PTR_ERR(hcd->phy_roothub) : -ENODEV;

Many (old) host controller drivers, their PHYs are not seen by software.
We may not consider NULL as error.

--=20

Thanks,
Peter Chen=